非乳頭部十二指腸粘膜下層浸潤癌の臨床病理学的特徴—内視鏡切除例を中心に

The Clinicopathological Characteristics of Non-ampullary Invasive Duodenal Carcinoma

要旨●非乳頭部十二指腸粘膜下層浸潤癌（SM癌）の臨床病理学的特徴を明らかにするために，自験の非乳頭部十二指腸癌79例〔粘膜内癌（M癌）73例，SM癌6例〕を対象として検討を行った．SM癌では腫瘍径（23mm vs. 35mm，p＝0.096）では有意差はないものの大きい傾向にあり，周在性は1/2周以上（11% vs. 50%，p<0.05）が有意に多い傾向がみられた．拡大内視鏡やEUSによる診断精度は限られ，SM癌の深達度予測の難しさが確認された．形質発現は胃型がM癌で4.1%，SM癌で33.3%，腸型はM癌で11.0%，SM癌で33.3%，胃腸混合型はM癌で37.0%，SM癌では33.3%であり，2群で差はなかった．今回の検討ではSM癌の特徴を明らかにするには至らなかった．今後はさらなる症例数の蓄積と形質・組織型別解析が必要である．

　We analyzed 79 cases of nonampullary duodenal carcinoma at our institution to characterize the clinicopathological features of nonampullary submucosal invasive duodenal carcinoma（SM carcinoma）. The group comprised 73 intramucosal carcinomas（M carcinomas）and 6 SM carcinomas. Although the difference was not statistically significant, the SM carcinomas tended to exhibit larger tumor diameters（23 vs. 35mm, p＝0.096）. Circumferential involvement of 1/2 was significantly more frequent in SM carcinomas（11% vs. 50%, p<0.05）. The limited diagnostic accuracy of magnifying endoscopy and endoscopic ultrasonography made predicting the depth of invasion in SM carcinomas challenging. Regarding phenotypic expression, we observed the gastric phenotype in 4.1% of M carcinomas and 33.3% of SM carcinomas, the intestinal phenotype in 11.0% of M carcinomas and 33.3% of SM carcinomas, and the mixed phenotype in 37.0% of M carcinomas and 33.3% of SM carcinomas. No significant differences in phenotypic expression were observed between the two groups. Although this study could not completely characterize SM carcinomas, further studies with larger sample sizes and analyses focusing on phenotypes and histological types will help clarify their distinctive features.